Electric motor



O. H. AND A. F. PIEPER. ELECTRIC MOTOR.

APPLICATION FILED NOV-12,1917.

1 ,348 ,239, Patented Aug. 3, 1920.

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( nal application filed UNITED STATES PATENT OFFICE.

OSCAR H. PIEPER AND ALIHONSE F. PIEPER, OF ROCHESTER, NEW YORK.

Specification of Letters Patent.

Original application filed May 27, 1912, Serial No. 699,938. Divided andthis application filed November 12, 1917. Serial No. 201,546.

To all whom it may concern: Be it known that we, OSCAR H. PIEPE andALrHoNsE F. PIEPER, of Rochester, in the county of Monroe and State ofNew York, have invented certain new and useful Improvements in ElectricMotors; and We do hereby declare the following to be a full, clear, andexact description of the same, reference being had to the accompanyingdrawings," forming a part of this specification, and to thereference-numerals marked thereon.

The invention has for its object to afford a cover for electric motorswhich will be free from noise and also dust-proof, so as to entirelyprotect the motor and motor casing within. The invention is especiallyapplicable to small motor construction such as used generally in dentalsurgery, and an equally important purpose is to provide a constructionwhich can be economically manufactured and is otherwise adaptedpractically to accomplishing the functions before stated. To these andother ends the invention resides in certain improvements andcombinations of parts all as will be hereinafter more fully described,the novel features being pointed out the end of the specification.

In the drawings: Figure 1 is a side elevation partly insection showingan electric motor equipped with the invention; 7

Fig. 2 is an enlarged sectional View in detail of the joint at the upperportion of the Cover section appearing in Fig. 1, and

V Fig. 3 is an enlarged sectional view of the joint at the lowerportion' of the cover section.

Similar reference numerals throughout the several views indicate thesame parts. This application is a division of an origib us May 27, 1912,Serial N o.' 699,938. The structure} here shown comprises a motor shaft1, armature 2 and motor casing or frame 3 upon which the field issupported, as usual in structures of this character. The cover whichsurrounds the motor 'casing is preferably formed of a fixed centralsection 4, and removable end sections 5 and 6 which are held in place inthe following manner. 7 designate annular supporting members which arefixedly attached to the casing 3 through the instrumentality of inwardlyprojecting in theclaims at edge of the -silient material, which flanges8 and are provided with outwardly projecting flanges 9 to which the.central section 4 is attached, the latter being provided with inwardlyprojecting flanges 10 which are spun over the flanges 9. The endsections 5 and 6 are both attached in a similarmanner and forthe presentpurpose it will suflice to describe only one of these.

The cover section 6 has fixed thereon at its inner edge an annular plate11 provided with an inwardly projecting flange 12. The inner surfaces ofthe plate 11 and flange 12 engage a body or ring of resilient materialsuc for example, as felt, designated by 13 and resting upon the flange9. This resilient packing cooperates with the flange 12 to'form acompletely noiseless and dustproof joint. To accomplish this, thesection 6 must be forced toward the resilient packing element 13, andthis is effected by means of a threaded retaining ring or nutll whichengages the reduced end or bearing of the casing 15 and is adjustablethereon in order to exert a pressure against the ranged to oppose acorrespondingly in- -clined flange 17 on the cover section 6, the flange17 being formed by bending the outer section slightly in an inwarddirection. Disposed between the flange 17 and the nut 14 is a packingring 18 of repermits a tight pressure. against the section 6 andat thesame time prevents direct Contact between it and the nut 14. Byadjusting the retaining ring 14;, the cover section 6 can be adjustedwith any desired degree of pressure against the packing ring 13, and isthus held rigidly in position. Dust or dirt is entirely excluded fromthe motor casing and all noise which might otherwise result from aloosely held cover with relatively moving contacting metallic portions,is obviated.

We claim as our invention:

Patented Aug. 3, 1920.

1. The combination with an electric annular supportingsupportingthreaded on the casing for holding the cover in position and clampingsaid ring of resilient material between said flanges.

2. The combination motor casing of a circular supporting flange fixed onthe casing, a ring of resilient material arranged on said supporting acover section carrying an inwardly projecting flange which rests on saidring of: resilient material, a retaining ring threaded on the casing forholding the cover section in position, an integral inwardly bent flangeformed on the section adjacent with an electric to said retaining ring,and resilient material interposed between said last mentioned flange andthe retaining ring.

3. The combination with an motor casing, to said casing, a supportingflange secured to said casing and engaging said central section, asecond'cover section, a ring having an inwardly projecting flangesecured in said second cover section, and a packing ring clamped betweensaid flanges.

OSCAR H. PIEPER. ALPHONSE F. PIEPER.

electric a central 'cover section fixed

